The present invention relates generally to golf clubs, and is particularly concerned with a method of making a golf club head having a sole plate of non-metallic material.
Up to now, most golf club heads have had metal sole plates. In many cases, the entire head is of metal. Some club heads are made of non-metallic materials, but these often have a metal sole plate. U.S. Pat. No. 4,795,159 of Nagamoto describes a wood-type golf club head formed from a shell of fiber reinforced plastic. A sole plate is secured to the lower face of the shell, the plate having an outer layer of metallic material and an inner layer of synthetic resin material.
One disadvantage of metal sole plates is that the weight of the metal tends to lower the center of gravity of the golf club head. As the center of gravity is lowered, the trajectory of the golf ball is higher. Professional or very low handicap golfers have to go to very low loft clubs in order to overcome the high trajectory resulting from a heavier sole plate. Low loft clubs, i.e. of the order of 7 to 7.5 degrees, allow the high swing speed, low handicap golfer to overcome the trajectory problem, but in doing so they will strike more errant shots than would have been made if they were to use a higher loft club with a 9 or 10 degree loft angle.
U.S. Pat. No. 5,342,812 of Niskanen et al. describes a golf club head which is entirely or partially made of ceramic or matrix metal composite material. The club head has a hollow body with an open lower end over which a sole plate is secured. Both the body and the sole plate may be of ceramic matrix composite material.